| John Adams Harper | |
| State1: | New Hampshire |
| District1: | At-large |
| Term Start1: | March 4, 1811 |
| Term End1: | March 3, 1813 |
| Preceded1: | Nathaniel A. Haven |
| Succeeded1: | Roger Vose |
| Office2: | Member of the New Hampshire House of Representatives |
| Term2: | 1809-1810 |
| Office3: | Member of the New Hampshire Senate |
| Term3: | 1805-1808 |
| Birth Date: | 2 November 1779 |
| Resting Place: | Union Cemetery Laconia, Belknap County New Hampshire, United States |
| Profession: | Farmer Innkeeper Surveyor Politician Judge |
| Party: | Democratic-Republican |
| Alma Mater: | Phillips Exeter Academy |
| Allegiance: | United States |
| Branch: | New Hampshire State Militia |
| Service Years: | 1809–1812 |
John Adams Harper (November 2, 1779 – June 18, 1816) was an American politician and a United States Representative from New Hampshire.
Born in Derryfield, New Hampshire, Harper attended Phillips Exeter Academy in 1794. He studied law and was admitted to the bar about 1802, commencing practice in Sanbornton.
Harper was the first postmaster of Sanbornton, then moved to Meredith Bridge (now Laconia, Belknap County) in 1806. He served as clerk of the New Hampshire Senate, 1805–1808, was a member of the New Hampshire House of Representatives[1] in 1809 and 1810. He served in the State militia, 1809–1812.
Elected as a Democratic-Republican to the Twelfth Congress, Harper served as United States Representative for the state of New Hampshire from (March 4, 1811 – March 3, 1813). He supported the Declaration of War in June 1812, and was an unsuccessful candidate for reelection in 1812 to the Thirteenth Congress.[2]
Harper died at Meredith Bridge (now Laconia), New Hampshire, on June 18, 1816, (age 36 years, 229 days). He is interred in Union Cemetery, Laconia, Belknap County, New Hampshire.